Safety-fuse.



PATENTED DEC! 24, 1907. J. SACHS & F. D. REYNOLDS.

SAFETY FUSE. APPLI'OATION FILED A1 15, 1906. RENEWED MAY 18, 1907.

WM am 25514 VE. i? Ma WATTV N R x JOSEPH SACHS AND FRANK D. REYNOLDS, OF HARTFORD, CONNECTICUT, ASSIGNORS TO THE UN TE-D STATES PATENT OFFICE."

SACHS COMPANY, OF HARTFORD, CONNECTICUT, A CORPORATION OF CONNECTICUT.

SAFETY-FUSE.

Specification of Letters Patent.

Patented. Dec. 24,1907.

Application filed April| 19061 Serial'No. 310.045. Renewed May 16, 1907. Serial No. 373,981-

' To allwhom it may concern: F Be it known that We, Josnrn SACHS and FRANK D. RnYNoLns, bothcitizens of the .which instead of merely connected across the terminals of the fuse and either wholly without the casing or partially within and partially outside the casing,

or entirely within the casing and having associated therewith means in an aperture and extending through the casing to thegyisible surface thereof for indicating the condition eating wire, thus making a secondary indiin so doing We employ a caps or ferrules therefor, ally connected to of thefuse strip,we employ a wire within -the casing of the fuse device which provides therein a shunt circuit across the end caps.

or fuse strip'terminals, and an indicating portion at one end located between one of he said end caps and the adjacent portion of'the fuse casing.

.30 'wire'has been directly connected in 'f'shunt In almost all cases where the indicating across the terminals of the fuse device,.the indication wasobtaincd by a portion or all of the wire being visible or by separate means affected by the rupture of the indication.

In carrying out our present invention we produce a means of indication which is diroot and positive instead of secondary, and tube or casing, end a fuse strip electricthe said end caps, a wire electrically connected at one end to one of the end caps and a connection of conducting material preferably of high resistance interposed between the inside of the other end cap and the opposite end of the said wire; and said conductin high resistance connection is preferably 0 such composition as to be changed, discolored, disrupted or otherwise aifected by the current to provide a means of indication.

In the drawing, Figure 1 is a central iongitudinal section of a safety fuse embodying :pletely filling the same our present invention. Fig. 2 is a plan of the same, showing a portion of one ofthe end caps broken away. Fig. 3 is a central longitudinal section of a safety fuse'embod'ying a modification of the resent invention; and Fig. 4 is a plan of t e same.

Referring to the drawings, a designates a casing preferably tubular and made of any suitable insulating material. Together with the casing a we employ end caps 1) adapted to fit over the respective ends' thereof and also fuse strip terminals 0 electrically connected to the said end caps, together with a fuse strip (1 extending between and electric ally connected with the said fuse strip terminals.

The outer surface of the tube a, at one end thereof 'may be provided with a recess 2, so placed that the greater portion thereof extends under and lies beneath the body of one of the end ca s b and within this recess and between'the ody of the end cap I) and-the adjacent portion of the tube a, We employ an indioatin connection 3 preferably made solely of car on, graphite or other material of low conductivity, or a mixture of the same and a small uantity of a suitable explosive or combusti 1e material, such as gunpowder. ,The material of which this connection is made may be either in loose or solid condition and applied in any suitable manner.

c designates a wire electrically connected at one end with one of the end caps 11 and is passed longitudinally through the tube a, through a slit or notch 4 provided in the opposite end of the tube a, and into the recess 2, the other end. of the said Wire being at the base of the recess with the indicating connection completing the circuit to the inside of the end cap.-

It will be understood that thewire e may be of any suitable metal and need not necessarily be of high resistance, since it is connected tion 3 which is of the necessary resistance to form with the wire 6, the required shunt around the main 'fuse wire. We are therefore enabled to make this wire 6 of materially greater section and hence more sub- 105 stantial than has heretofore been possible where the. indicating wine embodied the entire resistance of the shunt circuit. The connection 3 is-placed in the recess 2, comand extending bein series with the indicating connecthe inside of an end cap and one end of the I wire, the current passes through the indicatpartially covered with a drop of' white paint ber independently into a strip or plate indiyond the edge of the end cap and coming flush with the surface of the tube a, and that poi'tion of the connection extending beyond the edge of the ferrule may be covered or cated at 5, Figs. 3 and 4, and made of paper or cloth or other similar material impregnated with a suitable .mix ture of combustible and high resistance conducting material and adapted to be interposed between wire e as illustrated. e preferably employ a filling of an insulating material in a loose condition indicated atf- In operation after the blowing of the fuse ing connection by way of the wire 6 and the heating of the connection Sby the current, causes it to burn, disrupt, discolor, explode or otherwise indicate directly or indirectly, the blowing of the fuse.

A notable advantage of our indicator will be found in the fact that it may be of very high resistance and made to operate with extremely small current, hence, it can be used with fuses of small carrying capacity without affecting their normal rating and due to its direct operation,'failure to indicate is practically eliminated. 7

By locating the indicating connection within the end cap, it is protected from injury and when it is not desirable to cut the end of the tube to provide the recess, it can' be provided in the end cap.

It will be noted in the construction shown in the drawings that the end caps act as contact terminals for the completed fuse device but we do not limit ourselves to this specific arrangement as it will be understood that any other form of external contact terminal 1 may be used either in conjunction with end 1 caps or in any other suitable manner. We also do not limit ourselves to the particular I manner in which the wire 0 is connected at the non-indicating end nor do we wish to limit ourselves to the particular manner in which the indicating connection is made between the other end of said wire and one end 1 cap.

\Ye claim as our invention:

1. A safety fuse comprising a tube, end caps therefor, a fuse strip within the tube, a. i

wireelectrically connected at one end to-one of the said end caps, and indicating means electrically interposed between the other end of said wire and the other end cap.

2. A safety fuse comprising a tube, end caps therefor, fuse strip terminals electrically connect-edto the said end caps, a fuse strip extending between and electrically connected with the saidfuse strip terminals, a wire electrically connected at one end to one of the said end caps, and an indicating meanselectrically interposed between the other end of the said wire and the other end ca 3. A s fety fuse comprising a tu e, end caps thei-Efor, a fuse strip, a wireelectrically connecte at one end to one of the said end caps, and an indicating connection interposed between and electrically connected to the otheri end cap and the other end of said wire.

A. A safety fuse comprising a tube, end capstherefor, fuse strip terminalselectrically connected to said end caps, a fuse strip extending between and electrically connected with the said fuse strip terminals, a wire electrically connected at one end to one of the said end caps, and an' indicating connection interposed between and electrically connected to the other end cap and the other end of the said wire.

5. A safety fuse comprising a tube provided with a recess in its outer surface and at one end thereof, end caps for the said tube, a fuse strip, a wire connected at one end to one of the said end caps, and an indicating connection within the said recess in the casing, and interposed between the other end cap and' the opposite end of the said wire.

6. A safety fuse comprising a tube provided with a recess in its outer surface at one end thereof, end caps for the said tube, fuse strip terminals electrically connected to the said 1 end caps, afuse strip extending between and electrically connected with the said fuse strip terminals, a wire electrically connected at one end to one of the said end caps, and an indicating connection within the said recess in the casing and interposed electrically between the' other end cap and the opposite end of said wire.

7. A safety fuse comprising a tube, end caps therefor, a fuse strip, a conductor connected at one end with one of said end caps, and means interposed between the other end cap and the opposite end of the said conductor for indicating the blowing of the fuse.

S. A safety fuse comprising a tube, having a recess in its outer surface at one end thereof, end caps for said tube, the recess in the tube being of such an extent as to lie beneath the body portion of one of the end caps and to' extend beyond the edges of the same, a fuse strip, a conductor connected at one end to 1 one of the end caps, and means within said recess and interposed between the other end {136 fuse strip, a conductor connected atone end to one of the end caps, and an indicating connection within said recess and electrically ,mterposed between the other end cap and the opposite end of the said conductor.

10. A'safety fuse comprising a tube having a recess in its outer surface at one end thereof, end caps for, the said tube, the recess in the tube being partlybeneath one of the end caps and extending'beyond the edge of the same, a fuse strip, a conductor connected at one end to one of theend caps and an indicating connection of resistance material filling said recess and electricall interposed between the other end cap 81H the opposite end of the said conductor.

1 1. A safety fuse comprising a tube haying a. recess in its outer surface at one end thereof, end caps for said tube, the recess in the tube being of such an extent as to lie beneath the body to extend eyond the edge of the same, a fuse strip, a conductor connected at one end to one of the end caps, and an indicating connection of a mixture of combustible and re- .sistance material within said recess and elec trically interposed between the other end cap and the opposite end of the said conductor. 12. Asafety fuse comprising a tube, end caps therefor, a fuse strip within the tube, a wire electrically connected at one end to one of said end caps, and indicating means electrically interposed. between'the other. end of said wire and the other end cap and located between the inside of the end cap and the tube. 1

portion of one of the end caps and 13. A safety fuse comprising a tube, end caps for said tube, there being a recess between one of said end caps and one end of said tube, a fuse strip within the tube with its ends electrically connected to the end caps, a conductor connected at one end to one of said end caps, and an indicating connection electrically interposed between the other end cap and the opposite end of said conductor and located in the recess but havinga portion extending visibly beyond the edge of the end cap.

14. A safety fuse comprising a tube, end

caps therefor, a fuse strip within the tube, a conductor electrically connecte to one end of said end caps, and an indicating connection of conducting material inside of the other end cap and between it and the other end of said conductor, a portion of said connection being visible.

15. An indicator for inclosed safety fuse consisting of a wire electrically connected at one end to one terminal of said fuse and having an indicating connection interposed between its other end and the other terminal of said fuse, said connection being within the inclosing structure of the fuse.

16. A safety fuse comprising a tube, end caps therefor, a fuse strip within the tube, a wire electrically connected at one end to one of said end caps, andan indicating connection of a mixture of combustible and resistance niaterial electrically inter osed between the other end of said wire an the other end cap and located between the inside of the end cap and the tube.

Signed by us this 28th day of March 1906.

JOSEPH SACHS. FRANK D. REYNOLDS Witnesses:

FRANK M. ALLEN, JAMES B. CLARK. 

